#include<iostream>
#include<math.h>
#include<string>

using namespace std;

int main() {

	string sum = "142857";
	int n = 0;
	cin >> n;

	string ans = "0.";
	if (n == 0) {
		cout << "0" << endl;
	}
	else if (n == 6) {
		ans += sum;
		cout << ans << endl;
	}
	else if (n < 6) {
		ans += sum.substr(0, n);
		cout << ans << endl;
	}
	else {
		int div = n / 6;
		int amari = n % 6;
		for (int i = 0;i < n-1;i++) {
			ans += sum;
		}
		if (amari != 0) {
			string str = sum.substr(0, amari);
			ans += str;
		}
		cout << ans << endl;
	}

	return 0;
}